40 



Family DOLATOCRINID^E. 



DOLATOCKINUS DISPAK, n. Sp. 



Plate If, Fig. 27, side view; Fig. 28, basal view; Fig. 29, sum 



mif view. 



Species below medium size. Calyx low, somewhat bowl- 

 shaped, gradually expanding from a truncated base to the free 

 arms, without constriction. Radial ridges sharply angular and 

 bear a sharp node, at the middle of each plate. There is also 

 a sharp node on each interradial and a few obscure radiating 

 1'nes. The primary radials bear no radiating lines. Column 

 round and contains a large cinque foil canal. 



Basal disc pentagonal, one fourth wider that the diameter of 

 the column, and contains the concavity into which the end of 

 the column is inserted. First primary radials nearly as long 

 as wide and each one bears a long central node, on the points 

 of which the calyx will rest. Second primary radials wider 

 than long, quadrangular. Third primary radials smaller than 

 the second, pentagonal, axillary, and, in the ray on the right 

 of the azygous area, support on the distal side two secondary 

 radials and on the proximal side a single secondary radial, 

 that is axillary, and supports on each upper side a single ter- 

 tiary radial, and, in the ray on the left of the azygous area, 

 supports on the proximal side two secondary radials and on 

 the distal side a single secondary radial that is axillary, and 

 supports upon each upper side a single tertiary radial, which 

 gives to each of these rays three arms. In each lateral ray, 

 the third primary radial supports on each upper side a single 

 secondary radial, which is axillary and supports on each upper 

 side a tertiary radial which arrangement gives to each of these 

 two rays four arms. In the ray opposite the azygous area the 

 third primary radial bears upon each upper side two secondary 

 radials which gives to this ray two arms. There are, there- 

 fore, sixteen arms in this species. The arm formula is 3-)- 4 + 

 2+4+3. 



The azygous area is substantially like the other areas. The 

 first interradials are the largest plates in the calyx, have 

 eleven sides, and are followed by three plates in the second 

 range that unite with the plates of the vault. 



